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[PATCH 52/97] virtio-balloon: Use temporary PBP only
From: |
Michael Roth |
Subject: |
[PATCH 52/97] virtio-balloon: Use temporary PBP only |
Date: |
Tue, 1 Oct 2019 18:45:31 -0500 |
From: David Hildenbrand <address@hidden>
We still have multiple issues in the current code
- The PBP is not freed during unrealize()
- The PBP is not reset on device resets: After a reset, the PBP is stale.
- We are not indicating VIRTIO_BALLOON_F_MUST_TELL_HOST, therefore
guests (esp. legacy guests) will reuse pages without deflating,
turning the PBP stale. Adding that would require compat handling.
Instead, let's use the PBP only temporarily, when processing one bulk of
inflation requests. This will keep guest_page_size > 4k working (with
Linux guests). There is nothing to do for deflation requests anymore.
The pbp is only used for a limited amount of time.
Fixes: ed48c59875b6 ("virtio-balloon: Safely handle BALLOON_PAGE_SIZE < host
page size")
Cc: address@hidden #v4.0.0
Suggested-by: Michael S. Tsirkin <address@hidden>
Signed-off-by: David Hildenbrand <address@hidden>
Message-Id: <address@hidden>
Reviewed-by: Michael S. Tsirkin <address@hidden>
Signed-off-by: Michael S. Tsirkin <address@hidden>
Acked-by: David Gibson <address@hidden>
(cherry picked from commit a8cd64d488325f3be5c4ddec4bf07efb3b8c7330)
Signed-off-by: Michael Roth <address@hidden>
---
hw/virtio/virtio-balloon.c | 21 +++++++++------------
include/hw/virtio/virtio-balloon.h | 3 ---
2 files changed, 9 insertions(+), 15 deletions(-)
diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c
index 49999d0bbe..bd54e302de 100644
--- a/hw/virtio/virtio-balloon.c
+++ b/hw/virtio/virtio-balloon.c
@@ -34,11 +34,11 @@
#define BALLOON_PAGE_SIZE (1 << VIRTIO_BALLOON_PFN_SHIFT)
-struct PartiallyBalloonedPage {
+typedef struct PartiallyBalloonedPage {
ram_addr_t base_gpa;
long subpages;
unsigned long *bitmap;
-};
+} PartiallyBalloonedPage;
static void virtio_balloon_pbp_free(PartiallyBalloonedPage *pbp)
{
@@ -68,11 +68,11 @@ static bool
virtio_balloon_pbp_matches(PartiallyBalloonedPage *pbp,
}
static void balloon_inflate_page(VirtIOBalloon *balloon,
- MemoryRegion *mr, hwaddr mr_offset)
+ MemoryRegion *mr, hwaddr mr_offset,
+ PartiallyBalloonedPage **pbp)
{
void *addr = memory_region_get_ram_ptr(mr) + mr_offset;
ram_addr_t rb_offset, rb_aligned_offset, base_gpa;
- PartiallyBalloonedPage **pbp = &balloon->pbp;
RAMBlock *rb;
size_t rb_page_size;
int subpages;
@@ -149,12 +149,6 @@ static void balloon_deflate_page(VirtIOBalloon *balloon,
rb = qemu_ram_block_from_host(addr, false, &rb_offset);
rb_page_size = qemu_ram_pagesize(rb);
- if (balloon->pbp) {
- /* Let's play safe and always reset the pbp on deflation requests. */
- virtio_balloon_pbp_free(balloon->pbp);
- balloon->pbp = NULL;
- }
-
host_addr = (void *)((uintptr_t)addr & ~(rb_page_size - 1));
/* When a page is deflated, we hint the whole host page it lives
@@ -336,6 +330,7 @@ static void balloon_stats_set_poll_interval(Object *obj,
Visitor *v,
static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq)
{
VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
+ PartiallyBalloonedPage *pbp = NULL;
VirtQueueElement *elem;
MemoryRegionSection section;
@@ -344,7 +339,7 @@ static void virtio_balloon_handle_output(VirtIODevice
*vdev, VirtQueue *vq)
uint32_t pfn;
elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
if (!elem) {
- return;
+ break;
}
while (iov_to_buf(elem->out_sg, elem->out_num, offset, &pfn, 4) == 4) {
@@ -373,7 +368,7 @@ static void virtio_balloon_handle_output(VirtIODevice
*vdev, VirtQueue *vq)
if (!qemu_balloon_is_inhibited()) {
if (vq == s->ivq) {
balloon_inflate_page(s, section.mr,
- section.offset_within_region);
+ section.offset_within_region, &pbp);
} else if (vq == s->dvq) {
balloon_deflate_page(s, section.mr,
section.offset_within_region);
} else {
@@ -387,6 +382,8 @@ static void virtio_balloon_handle_output(VirtIODevice
*vdev, VirtQueue *vq)
virtio_notify(vdev, vq);
g_free(elem);
}
+
+ virtio_balloon_pbp_free(pbp);
}
static void virtio_balloon_receive_stats(VirtIODevice *vdev, VirtQueue *vq)
diff --git a/include/hw/virtio/virtio-balloon.h
b/include/hw/virtio/virtio-balloon.h
index 5a99293a45..d1c968d237 100644
--- a/include/hw/virtio/virtio-balloon.h
+++ b/include/hw/virtio/virtio-balloon.h
@@ -33,8 +33,6 @@ typedef struct virtio_balloon_stat_modern {
uint64_t val;
} VirtIOBalloonStatModern;
-typedef struct PartiallyBalloonedPage PartiallyBalloonedPage;
-
enum virtio_balloon_free_page_report_status {
FREE_PAGE_REPORT_S_STOP = 0,
FREE_PAGE_REPORT_S_REQUESTED = 1,
@@ -70,7 +68,6 @@ typedef struct VirtIOBalloon {
int64_t stats_last_update;
int64_t stats_poll_interval;
uint32_t host_features;
- PartiallyBalloonedPage *pbp;
bool qemu_4_0_config_size;
} VirtIOBalloon;
--
2.17.1
- [PATCH 26/97] target/ppc: Fix xvabs[sd]p, xvnabs[sd]p, xvneg[sd]p, xvcpsgn[sd]p, (continued)
- [PATCH 26/97] target/ppc: Fix xvabs[sd]p, xvnabs[sd]p, xvneg[sd]p, xvcpsgn[sd]p, Michael Roth, 2019/10/01
- [PATCH 27/97] target/ppc: Fix xvxsigdp, Michael Roth, 2019/10/01
- [PATCH 53/97] virtio-balloon: don't track subpages for the PBP, Michael Roth, 2019/10/01
- [PATCH 48/97] virtio-balloon: Fix QEMU crashes on pagesize > BALLOON_PAGE_SIZE, Michael Roth, 2019/10/01
- [PATCH 51/97] virtio-balloon: Rework pbp tracking data, Michael Roth, 2019/10/01
- [PATCH 55/97] i386/acpi: fix gint overflow in crs_range_compare, Michael Roth, 2019/10/01
- [PATCH 64/97] iotests: Test backup job with two guest writes, Michael Roth, 2019/10/01
- [PATCH 68/97] iotests: Test unaligned blocking mirror write, Michael Roth, 2019/10/01
- [PATCH 58/97] block/backup: simplify backup_incremental_init_copy_bitmap, Michael Roth, 2019/10/01
- [PATCH 60/97] block/backup: refactor and tolerate unallocated cluster skipping, Michael Roth, 2019/10/01
- [PATCH 52/97] virtio-balloon: Use temporary PBP only,
Michael Roth <=
- [PATCH 05/97] qcow2: Fix qcow2_make_empty() with external data file, Michael Roth, 2019/10/01
- [PATCH 69/97] block/backup: disable copy_range for compressed backup, Michael Roth, 2019/10/01
- [PATCH 78/97] iotests: Add supported protocols to execute_test(), Michael Roth, 2019/10/01
- [PATCH 07/97] cutils: Fix size_to_str() on 32-bit platforms, Michael Roth, 2019/10/01
- [PATCH 80/97] iotests: Restrict nbd Python tests to nbd, Michael Roth, 2019/10/01
- [PATCH 41/97] docs/bitmaps: use QMP lexer instead of json, Michael Roth, 2019/10/01
- [PATCH 54/97] virtio-balloon: free pbp more aggressively, Michael Roth, 2019/10/01
- [PATCH 56/97] tpm: Exit in reset when backend indicates failure, Michael Roth, 2019/10/01
- [PATCH 88/97] curl: Check completion in curl_multi_do(), Michael Roth, 2019/10/01
- [PATCH 87/97] curl: Keep *socket until the end of curl_sock_cb(), Michael Roth, 2019/10/01